Word Gwen made up to drive us B-A-N-A-N-A-S trying to figure out what it means.

gwen: Hey i have an idea... i will make up a word that nobody really knows the meaning of and put it in a song and try to make people figure out what it means. it will drive them bananas. oh! I should put that in the song too!!

It seems as though Ms. Stefani has had some incidents in which another young, presumably female, individual has made some disparaging remarks about her character. Upon learning of the situation, Ms. Stefani is informing this “culprit” that she intends to handle this matter physically. Ms. Stefani’s character is such that she is not the type of person who counters verbal attacks with verbal attacks, or “hollering back.” Using terminology that is commonplace among today’s youth, this is shortened to “hollaback.” Additionally, it appears as though this altercation will take place somewhere near the bleachers.

lyrics:
I heard that you were talking shit
And you didn't think that I would hear it
People hear you talking like that, getting everybody fired up
So I'm ready to attack, gonna lead the pack
Gonna get a touchdown, gonna take you out
That's right, put your pom-poms downs, getting everybody fired up

A female, usually a teenager or young adult, who, when insulted, will reply verbally. This is typically achieved by insulting the original insulter (otherwise known as 'hollering back', shortened in this case to 'hollaback').

This term was popularized by Gwen Stefani, a female vocalist who once performed lead vocals for a rather good band, No Doubt. Gwen has since gone solo, which people either love or hate, depending on how much they suckle upon the mainstream teet.

In her song "Hollaback Girl", Gwen proclaims, when challenged by another girl (even though Gwen can hardly be described as a girl) through insults, that she "Ain't no hollaback girl". This is because Gwen is not a girl, but a woman, isn't going to stand for this, and is going to settle it physically.

(Note: The song, from this point, degrades into the usual Gwen Stefani lyrics: pointless, annoying, and unbearably catchy).

Provided with links to other definitions one might need to understand the situation:

NOUN: A girl that is willing to be treated like a doormat or booty call. She is a girl that will allow guys to do whatever they want with her and will just wait for them to 'holla back' at them.

VERB: a member of a cheerleading squad who repeats – hollers back - words that the squad leader shouts out to them.

Gwen Stefani uses the term brilliantly in her song "Hollaback Girl", both as a simile and a metaphor. She’s letting the guys know that she ain’t a booty call and that she’s not gonna be sitting around waiting for them to “holla back”. She’s “been around the track a few times” so it’s not gonna happen again. She uses the cheerleading terminology as a metaphor, she’s a “squad” leader not a follower.

Contrary to popular belief, this was not invented by Gwen Stefani. She wrote the song in response to a music journalist who made some catty remarks about how Gwen was a cheerleader in high school.
'I heard that u were talking sh!t and you didn't think that i would hear it'...
A hollaback girl is one of the backup, inferior cheerleaders. She was not one of those, but the leader.
'we both wanna be the winner but there can only be one'
Gwen Stefani was merely saying that yes, she was a cheerleader, but she was a damn good one!

a follower. Originally, a holla back girl was a member of a cheerleading squad who repeats – hollers back - words that the squad leader shouts out to them. Now, it means a girl doesn't stand up for herself, allowing guys to do whatever they want with her and she follows them, 'holla back' at them.

In the Gwen Stefani song, she uses the cheerleading terminology as a metaphor, she’s a leader & fighter, not a follower.

"Hollaback girl" is actually a mistaken lyric in the popular song by Gwen Stefani. What she is actually saying is "I ain't no Holland badger". Unlike the average omnivorous European badger, this badger, native to the Netherlands, is notorious for eating bananas (which is how it received its title "Meles meles musa"). Stefani clearly states that she is not a Holland badger, and therefore is not the type to eat bananas. She goes on to compare "shit" with "bananas", voicing her strong dislike for the fruit.

actual words to the song: "I ain't no Holland badger"
words most often misheard: "I ain't no hollaback girl"